By Tiernan Ray

After teasing last month that it had filed for an initial public offering, Twitter this evening filed the formal S1 prospectus, listing $317 million in revenue in 2012 and a $79 million net loss.

The deal, with a face value of $1 billion, is underwritten by Goldman Sachs, along with Morgan Stanley, J.P. Morgan, Bank of America, Deutsche Bank, Allen & Co. and CODE Advisors.

For the six months ended this year, the company made $253 million revenue and $69 million in net losses.

We have experienced rapid growth in our revenue in recent periods. From 2011 to 2012, revenue increased by 198% to $316.9 million, net loss decreased by 38% to $79.4 million and Adjusted EBITDA increased by 149% to $21.2 million. From the six months ended June 30, 2012 to the six months ended June 30, 2013, revenue increased by 107% to $253.6 million, net loss increased by 41% to $69.3 million and Adjusted EBITDA increased by $20.7 million to $21.4 million. For information on how we define and calculate Adjusted EBITDA, and a reconciliation of net loss to Adjusted EBITDA, see the section titled “—Summary Consolidated Financial and Other Data—Non-GAAP Financial Measures.

87% of Twitters revenue came from advertising in the first six months, the rest being “data licensing.”

Twitter notes that while it has had soaring engagement, the price of ads has dropped, largely because inventory has swelled:

The increase in advertising revenue per timeline view was primarily driven by a 199% increase in ad engagements per timeline view, partially offset by a 59% decrease in average cost per ad engagement in the six months ended June 30, 2013 compared to the same period in the prior year […] Average cost per ad engagement decreased 18%, 9%, 19%, 12% and 46% sequentially in the three months ended June 30, 2012, September 30, 2012, December 31, 2012, March 31, 2013 and June 30, 2013, respectively. The decreases in cost per ad engagement over these periods were primarily due to an increase in supply of advertising inventory available in our auctions, which was partially offset by increased demand for our Promoted Products. Supply of advertising inventory increased as we expanded the distribution of our Promoted Products to our mobile applications and additional markets outside of the United States in 2012. The increase in advertising inventory provided us with additional opportunities to place ads on our platform.

Through June of this year, Twitter had racked up an accumulated deficit of $418.6 million.

Regarding usage, the company remarks, “We have more than 215 million MAUs, and more than 100 million daily active users, spanning nearly every country.” The company defines an active user as someone following 30 or more people.

Here's the chart of growth in monthly uniques since March of 2012:

The company also notes its success with mobile:

Mobile has become the primary driver of our business. Our mobile products are critical to the value we create for our users, and they enable our users to create, distribute and discover content in the moment and on-the-go. The 140 character constraint of a Tweet emanates from our origins as an SMS-based messaging system, and we leverage this simplicity to develop products that seamlessly bridge our user experience across all devices. In the three months ended June 30, 2013, 75% of our average MAUs accessed Twitter from a mobile device, including mobile phones and tablets, and over 65% of our advertising revenue was generated from mobile devices. We expect that the proportion of active users on, and advertising revenue generated from, mobile devices, will continue to grow in the near term.

The price of ads, Twitter notes,

As recently as early August, the company's stock was valued at $20.62 per share, Twitter notes:

We determined the fair value of our common stock to be $20.62 per share as of August 5, 2013 based on the subject company transaction method. We utilized the arm’s-length transactions of our equity securities in the secondary market since our most recent common stock valuation date, May 15, 2013, to estimate the fair value of our common stock. Factors considered in this methodology included the number of shares sold, relationship of the parties involved, timing of the transactions in relation to the valuation date and our financial condition. The weighted-average transaction price of the recent secondary market common stock transactions was approximately $20.62 per share. Based on the valuation of our common stock completed in August 2013, the fair value of RSUs granted through September 5, 2013 was determined to be $20.62 per share.

CNBC's Kayla Tausche notes a short while ago that several insiders have large stakes in the company, including Jack Dorsey, executive chairman, has a 4.9% stake. Evan Williams, another founder, has a 12% stake. And Peter Fenton of Benchmark Capital has a 6.7% stake in the company.

About Tech Trader Daily

Tech Trader Daily is a blog on technology investing written by Barron’s veteran Tiernan Ray. The blog provides news, analysis and original reporting on events important to investors in software, hardware, the Internet, telecommunications and related fields. Comments and tips can be sent to: techtraderdaily@barrons.com.